1. Technical Field
This document relates to devices and methods for the treatment of heart conditions. For example, this document relates to a percutaneous temporary epicardial pacemaker device and system for treating heart arrhythmia.
2. Background Information
Patients with bradyarrhythmia may experience symptoms including dyspnea, lightheadedness, fatigue, presyncope, or syncope. The etiology of bradyarrhythmia is often sinus node dysfunction or a conduction disturbance. Some patients may have a transient cause of bradyarrhythmia such as electrolyte abnormalities or medication overdose. However, other patients have intrinsic conduction disease with conduction block occurring below the Bundle of His, and as such the heart beat is erratic, unstable, and unreliable.
For treatment, as part of advanced cardiac life support algorithms, patients are given atropine, which is generally ineffective for both transplanted hearts or in conduction disturbances that below the Bundle of His. Another treatment commonly given is a chronotropic agent such as dopamine or epinephrine.
If these medications fail to provide an adequate remedy, then transcutaneous pacing may be tried. Transcutaneous pacing is most commonly delivered by defibrillator pads applied to “anterior/posterior” or “right chest/left axilla” locations of the patients. The defibrillator is then able to pace the patient's heart using high energy in its pacing mode. This pacing may be uncomfortable for many patients, as it results in skeletal muscle contractions synchronous with the pacing. The effectiveness of the pacing is limited by contact of the defibrillator pads with the skin (such as by hair), larger body habitus, and COPD which limit the current delivery to the heart.
If transcutaneous pacing fails to provide an adequate remedy, then transvenous pacing may be tried. Placement of a temporary pacemaker wire transvenously may require placement of a central line under fluoroscopy (with the requisite leaded apron protection and additional personnel such a radiology tech). Depending on the type of temporary pacemaker placed, there may be barriers to the placement, including technical expertise to achieve the placement, tricuspid regurgitation, and vein occlusion. The transvenous pacing lead may become dislodged after completion of the placement procedure, and this requires additional fluoroscopy to reposition the transvenous lead.
If there are no reversible etiologies for the symptomatic bradycardia or high-grade conduction disturbances, a permanent pacemaker is indicated. For patients with mild symptoms due to these etiologies, there is time to work through the above treatment options. However, some patients have more severe symptoms and require more immediate treatment than allowable for placement of transvenous pacing systems, or they have more discomfort than necessary from the transcutaneous pacing pads.